7.2.1 Plain Integer Objects

PyIntObject
This subtype of PyObject represents a Python integer object.

PyTypeObject PyInt_Type
This instance of PyTypeObject represents the Python plain integer type. This is the same object as types.IntType.

int PyInt_Check(PyObject *o)
Return true if o is of type PyInt_Type or a subtype of PyInt_Type. Changed in version 2.2: Allowed subtypes to be accepted.

int PyInt_CheckExact(PyObject *o)
Return true if o is of type PyInt_Type, but not a subtype of PyInt_Type. New in version 2.2.

PyObject* PyInt_FromString(char *str, char **pend, int base)
Return value: New reference.
Return a new PyIntObject or PyLongObject based on the string value in str, which is interpreted according to the radix in base. If pend is non-NULL, *pend will point to the first character in str which follows the representation of the number. If base is 0, the radix will be determined based on the leading characters of str: if str starts with '0x' or '0X', radix 16 will be used; if str starts with '0', radix 8 will be used; otherwise radix 10 will be used. If base is not 0, it must be between 2 and 36, inclusive. Leading spaces are ignored. If there are no digits, ValueError will be raised. If the string represents a number too large to be contained within the machine's long int type and overflow warnings are being suppressed, a PyLongObject will be returned. If overflow warnings are not being suppressed, NULL will be returned in this case.

PyObject* PyInt_FromLong(long ival)
Return value: New reference.
Create a new integer object with a value of ival.

The current implementation keeps an array of integer objects for all integers between -1 and 100, when you create an int in that range you actually just get back a reference to the existing object. So it should be possible to change the value of 1. I suspect the behaviour of Python in this case is undefined. :-)

long PyInt_AsLong(PyObject *io)
Will first attempt to cast the object to a PyIntObject, if it is not already one, and then return its value.

long PyInt_AS_LONG(PyObject *io)
Return the value of the object io. No error checking is performed.

unsigned long PyInt_AsUnsignedLongMask(PyObject *io)
Will first attempt to cast the object to a PyIntObject or PyLongObject, if it is not already one, and then return its value as unsigned long. This function does not check for overflow. New in version 2.3.

unsigned long long PyInt_AsUnsignedLongLongMask(PyObject *io)
Will first attempt to cast the object to a PyIntObject or PyLongObject, if it is not already one, and then return its value as unsigned long long, without checking for overflow. New in version 2.3.

long PyInt_GetMax()
Return the system's idea of the largest integer it can handle (LONG_MAX, as defined in the system header files).

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